Acidity in Bottled Water

Recently I was asked about a video of someone promoting alkaline water by measuring the pH of bottled water. Most of the bottled waters measured were mildly acidic, with pH ranging from 6.50 to 7.00.

The question asked of me was if drinking that type of bottled water was safe.

For a relative idea of the impact of drinking a very mild acid:

Soft drinks have a typical pH of 2.52. The water bottles tested were around a pH of 6.50.

As a refresher from chemistry, acidity is based on the concentration of hydroxyl and hydronium present in the solution being tested. pH is literally defined as the negative base-10 logarithm of the hydronium concentration.

These ions react to form other compounds, which may or may not be a good thing, depending on what you want in your reaction. In the case of your body, we’ll discuss that in a minute. Anyway, hydroxyl and hydronium react to form water together. A neutral pH solution has equal parts hydroxyl and hydronium, which means they react entirely to form pure water.

Another point to quickly make is that pH is a logarithmic scale.

For an idea of the relative acidity:
Coke with a pH of 2.52 has approximately 2.951 mmol/L hydrogen ions
Slightly acidic water (pH of 6.50) is about 0.0003162 mmol/L of hydrogen ions.

That’s a difference of about 10,000x in terms of actual acidity, and yet your body seems to suffer no significant ill effects from drinking Coke (other than rotting your teeth [which is actually due to the low pH! Anything below 6.50 starts to dissolve dentin if you hold it in your mouth for long enough…and there’s also the fact that non-mineralized liquids decalcify your enamel which is why we add fluoride to water…] and gaining weight from the horrible amounts of sugar).

Homeostasis works to counteract any possible changes in your body from the pH liquid that you’re consuming.

In the interests of brevity, I’ll link to an article I wrote last year on the whole alkaline diet thing.

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